Furnace



May 26, lzs.

F. E. FLEMING FURNACE Filed Nov. 5, 1920 3 Sheets-Sheet 2 r11-1re@ i: r 'QWMM May 26, 1925.

F. E.- FLEMING FURNACE Filed Nov. 5, 1920 3 Sheets-She'et 5 chamber 1li Patented May 26, 1925.

UNITED STATES PATENT OFFICE;

FRANK E. FIEMING, OF DETROIT, MICHIGAN, ASSIGNOB TO THE UNDERFEED STOKER COMPANY OF AMERICA, 0F DETROIT, MICHIGAN, A CORPORATION 0F NEW JERSEY.

FURNACE.

Application filed November 'To all whom 'it may concern.'

Be it known that I, FRANK E. FLnMiNG, a citizen of the United States, residing at Detroit, in the county of 7Wayne and State of Michigan, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

My invention, in furnaces, relates more particularly in some of its aspects, tok furnaces for developing a. long flame, such as may desirablybe used for melting and an healing work, as well as with some sorts of steam boiler heaters.

Among its objects are to provide for autof matic stoking, with adequate and regulated fuel supply, proper fuel distribution and efficient fuel consumption, together with ease of cleaning. Other objects attained by my invention are simple and effective construction, durability,jand facility of repair and replacementof requisite parts, in a furnace ofthe character mentioned.

My invention Vis especially applicable in a furnace having a fire-box floor comprising a forward fuel-receiving coking-plate and a rear grate, so that fuelfed from front to rear through the lire-box may Apass unburned over the coking-plate, but giving off gases under the influence of the heat to which it is subjected from above and in front of it'and may thence pass onto the grate that is air-fed from below to support active combustion of a fuel. Vhile features of my invention maybe applied in various specific forms, I have shown only a single embodiment, in such a furnace, for purposes of disclosure, without intent to limit my invention specifically thereto.

In the drawings Fig. 1 is a longitudinal section of a furnace; Fig. 2 is a front elevation thereof with parts broken away; and Fig. 3 is a plan sectional view. Y

Front wall 10, bridge wall 11, side walls 12, and arch 13, appurtenant to combustion and also the sub-chamber 15a- 15b (which may bottom at-a basement level and which serves as an ash-chamber and also as a wind-chamber to which air under pressure may be supplied) may all be of such forms of brick-and-iron work as the particular installation may require. Access to the combustion chamber and to the ash chamber may be had from without, as by the provision of door-closed sight openings 5,1920. serial No. 422,043.

16 and 17 to the refbox and of an ash-pit opening 18. ,Preferably such closable openings are provided in theside-walls of the combustion chamber', in locations as illustrated, and Vin the front-wall of the ash-pit, for vreasons that will become apparent.

The floor of the lire -boX or combustion chamber has its forward coking-plate 20, arranged substantially horizontally and to eX- tend` about half the distanceto the bridge wall (although the proportionate` length 'of coking-plate and grate may vary somewhat to suit specific requirements) this coking' plate being cdead7 or sufficiently impervious to air from below to keep the green fuel from burning' thereon. "At its rear edge it meets a live or airpervious` shaking-grate 21, that preferably down-slopes longitudinally from front to rear, the arrangement shown locating the coking-plate about on a level with the bridgewall top but with the grate down-sloping to meet the bridge-Wall a suitable distance below its top.

I provide for force-feeding fuel longitudinally over such floor `from supply hoppers Q2 by abattery of rams23, reciprocatingly driven as by steam cylinders 24 (which may be individually controlled as to periodicity of operation, if desired, by known means, noty shown) to feed the fuel from the hop* pers through supply-throats'Q lonto the ooking-plate. VFor evenness of feed these fuelsupply-sources are `rather closetogether, so that jointly they have propulsive effect on practically all .of the fuel on the coking plate. It will be apparent that Lfuel, thus supplied, may bank upquite thickly on the coking-plate 2O and will gradually,"(but in impulses` or with thrusts that tend to prevent clinker formation at the front edge of the plate) be pushed forward onto the grate 21, there to burn; the consequent heating up of the combustion space and the reliection and radiation of heat from the arch causing the fuel on the coking-plate to release more or less of its gases which, sweeping forward over theactive lire, burn in long iames tha pass out over thebridge-wall. In the particular construction shown provision is made for some circulating air-sup-L ply to the cokingspace portion of the lirebox although in some instances such provision is not necessary` to the satisfactory sweeping of the fuel-gases into the flame Zone above the grate. Character 26 designates small air-ducts, dampered at 27, though the front wall, and 28 (F ig. 2) designates small air-openings through-the coking plate, these being designed vin size to supply only air for gas-movement, rather than to support combustion above the coking plate. Either or both forms of air-supply for circulation may be used.

As illustrated, the coking-plate may best be a generally horizontal plate, with a plurality of depressed parallel channels 30, curved transversely and spaced so as to register with the lowerarcs of the respective fuel-throats 25, and each channel being upsloped rather steeply near its rear end, as at 31. The fuel-directing and feed-resisting influences of such channel construction aid in the fuel-banking and condensation for coking purposes. The plate may be rigidly constructed of sections bolted together as at 32, and for support they may be flangebolted to the feed-throats at 33 and may rest on a transverse I-beam 34, so that the rearedge flange 35 of the plate will act as a stop for the movable grate 2l.

The shaking grate, pivoted as a whole at its rear end swings on a pivot rod 36 supported in brackets 37 mounted in the bridge wall, and is formed of laterally-rocking sections or grate-bars 38, transversely tiltable, so that the grate may be shaken to sift its ashes into the rear portion 152L of the ashpit, and may be lowered to dotted line portion (Fig. l) to dump its load into the front part 15b of the ash-pit and to permit of thorough cleaning and repair of the grate, and for preparing for re-charging of the furnace.

The grate specilicallyshown comprises a frame 40 with front and rear end-sills 41 and 42- connected by suitable side bars or braces 43, which if the rocking grate-bars are to be carried out clear to the sides of the grate, as shown, may be depressed below the 4level of the rocking Darts, such details being readily variable in design.` The rear sill has lugs 42 pivoted on rod 36 and the front sill has end-extensions 41 provided with bails 44 for connection with the hoisting tackle. v

The tops of the T-sectioned sills are grooved like scale-saddles and flanged to prevent longitudinal movement of the gratebars and in the groovesare fulcruined the sharp edges of the grate-bar-webs, such bars 38 being T-sectioned as shown. Each gratebar web has, about centrally of its length and below the level of its fulcra, either a yoke 45 to straddle, or a ring 45 to surround, a corresponding removable pin 46 on a shaker-bar 47 that is operatable from the side-exterior of the furnace. Of course engagement of the pins 46 with occasional Foot-lever extension 54 of link 52 facilitates restoration of such connection when the.l

grate is raised again. The grate is normally held in its raised position by a counterweight 55 working in a housing 56 on the.

exterior of the furnace and having cable. connection 57 running over suitable pulleys 57 to the bail 44 of the front sill extension of the grate. A lifting device 58 for. the

weight is provided, shown as hand-crank 59` sprocket-and-chain connected as at 60 with one of the pulleys for cable 57, the gearing being provided with a latch-ratchet 61 so that the weight may be held in any desired raised or partly-raised position. Of course the furnace-sidewalls may be channeled or recessed, as at 12a and 12b, to give the moving parts clearance wherever necessary, and when the width of the Stoker vmakes such provision desirable, the grate-lifting devices may be duplicated on opposite sides of the furnace, as herein shown.

In operation the green coal introduced by the rains 23 and banked up on the coking plate 2O to give ofll its more volatile gases for consumption as they pass over the area of active fuel combustion above grate 21, may be fed quite uniformly and regularly by the Stoker-rams over the whole width of the fire-box, but breakingV down of the coking mass near the front flange of the coking pla.te and other supervisory activities, may be manually performed, the normally closed openings 16 and 17 giving access for the use of slice-bars and other tools. The particular construction of coking plate tends to prevent the impulsively-rammed fuel from avalanehing down the inclined grate and also furthers the uniformity of fuel distribution and feed to the grate. The grate may be shaken for ash-removal during the run, to prevent too great a banking`- of ashes at the rear thereof, and when a run is finished the grate may be pivotally lowered to dump its fire, expose its grate-bars to cooling circulation of air, and position the grate for thorough cleaning and repair, if needed. The grate bars may be individually removed and replaced if need be, with minimum work while the grate stands lowered. ,During the, operation of the furnace slight partial lowering of the grate may be employed to give a draft more than normal above the grate at its front edge and accordingly to modify the combustion and coking conditions.

While I have herein'described a specific enlbodiment cf my invention in considerable detail, it will be understood that many changes in detail may be made Without departure from the spirit of my invention Within the scope of the appended claims.

I claim:

l. In a furnace of the character described the combination with coal feeding means adapted to propel fuel rearwardly through the lire boX, of a dead eoking plate forming the front of the fire-box floor, a live grate arranged to cooperate with the rear edge of the colzing plate; said grate pivoted at its rear edge for tilting toload-dumping position and comprising a frame, rocking grate bars pivoted thereon, and a shaker bar, means for operatingl said shaker bar disconnectible therefrom to permit grate-depression, and a countervveight operatively con nect'ed to the grate-frame to maintain it normally in raised position.

2. In a furnace, the combination of [ireboX Walls, means for feeding fuel through the front Wall, a coking plate adjacent to the front Wall, a grate pivoted at its rear edge and at its front edge coacting with said coking plate, said grate comprising a frame having front and rear sills, grate bars pivoted on said sills and a transverse shaker barconnected with and arranged to operate said grate bars; means for normally elevating the front end of said grate, movable to permit the grate to descend to dmnping position, and grate-shaking means located at a fixed elevation and having detachable connection With the shaker-bar.

3. In a furnace, the combination of lireboX walls, means for feeding fuel through the front Wall, coking plate adjacent to the front Wall, a grate pivoted at its rear edge, and at itsfront edge coacting With said coking plate, said grate comprising a frame having front and rear sills, grate bars detachably pivoted on said sills and a transverse shaker bar detachably connected with and arranged to operate said grate bars; means for normally elevating the front end of said grate, movable to permit the grate to descend to dumping position, and grateshaliing means located at a fixed elevation and having detachable connection With the shaker-bar whereby the grate bars may be individually removed While the grate is in dumping position.

FRANK E. FLEMING. 

